As a practically devout WoW/Blizzard fan, I'm disappointed in myself for taking so long to come around.
I love, love, love this game. Can't believe it was free. I'd have paid.
I'm having so much fun with just basic pre made decks and one custom one I made for the default/first class, Mage, that I'm not even feeling like earning gold for more content is grindy.
This is great. I haven't even really gotten into sophisticated deck tweaking or even tried any of the other classes yet. This game'll provide for a long, long time.
Again, I can't believe this was free. I know it relies on IAP for the expansion wings, but shit, the amount of fun, charm, polish and content here for the price tag of $0 is phenomenal.
Edit-
To the casual world at large, if something has Minions or Magic in it, it's nerdy.
If Warcraft is even slightly associated, it's nerdy.
If it's a video game or a spin-off of a video game, it's double-nerdy.
This is all of those things. This is a nerdy game. And I love it.